Steerable antenna assembly utilizing a dielectric lens

ABSTRACT

A steerable antenna assembly (“SAA”) for receiving a plurality of incident radio frequency (“RF”) signals at a plurality of incident angles is disclosure. The SAA includes an approximately spherical dielectric lens (“SDL”), a waveguide aperture block (“WAB”), a switch aperture matrix (“SAM”), and a radial aperture combiner (“RAC”). The SDL receives and focuses the plurality of incident RF signals creating a plurality of focused RF signals at a plurality of focal points approximately along the back surface of the SDL. The WAB is positioned adjacent to the back surface of the SDL and receives the plurality of focused RF signals. The SAM electronically steers a beam of a radiation pattern produced by the SAA and switch between the pluralities of focused RF signals based on electronically steering the beam. The RAC produces a received RF signal from the plurality of focused RF signals.

CROSS-REFERENCE TO RELATED APPLICATION AND CLAIM OF PRIORITY

The present patent application is a utility application, claimingpriority under 35 U.S.C. §119(e) to U.S. Provisional Application No.62/379,031, filed on Aug. 24, 2016, titled “User Terminal IncludingDielectric Lens With Waveguide Assembly and Method of Using,” to Savageet al., which is hereby incorporated by reference in its entirety.

BACKGROUND 1. Field

The present disclosure relates generally to antennas and, moreparticularly, to an antenna system utilizing a spherical lens and anantenna array to electronically scan the antenna system.

2. Related Art

The use of unmanned aerial vehicles (“UAVs”), commonly referred to asdrones, has experienced explosive growth in this decade. Most UAVsutilize wireless technologies to control and communicate data betweenthe UAV and a user terminal (“UT”). The control and data performance ofthis wireless link significantly limits the range, maneuverability andoverall functionality of the UAV. As UAV use has expanded, the wirelesslink capabilities have become a limiting factor in the UAV systemapplication space.

The UAV wireless link consists of radios and antennas at the userterminal and in the aircraft. The primary wireless “weak point” in thelink is the UT antenna. The UT antenna's ability to efficiently trackthe aerial vehicle in flight is a significant coverage and rangelimitation. Attempts to address this issue have included the use ofmultiple terrestrial UT locations, satellites, and mechanicallyarticulated antennas. The costs, complexity and logistics of multi-siteterrestrial systems has limited their application. Satellite systemcomplexity and data latency makes real-time control and observation ofUAVs extremely complex and expensive. Mechanically articulated antennashave significant response time and pointing accuracy issues tracking theaerial vehicle. In the area of operations of the UAV it is desired tohave a single UT system that can track the aerial vehicle efficiently atsufficient range to accomplish the operational objectives.

At present, one of the solutions to address the tracking latency issueis to utilize a phased array antenna which provides high antenna gainand electronically controlled steerability over the antenna field ofview. Phased array antennas are complex to setup and operate, consumelarge amounts of power, and are expensive so their practical applicationis limited to high-end systems. Therefore, there is a need for a costeffective advanced antenna design that addresses the UAV trackingproblem.

SUMMARY

Disclosed is a steerable antenna assembly (“SAA”) for receiving aplurality of incident radio frequency (“RF”) signals at a plurality ofincident angles. The SAA includes an approximately spherical dielectriclens (“SDL”), a waveguide aperture block (“WAB”), a switch aperturematrix (“SAM”), and a radial aperture combiner (“RAC”). The SDL includesa front surface and a back surface, where the SDL is configured toreceive and focus the plurality of incident RF signals to create aplurality of focused RF signals at a plurality of focal pointsapproximately along the back surface of the SDL. The plurality of focalpoints have positions along the back surface of the SDL that correspondto the plurality of incident angles of the plurality of incident RFsignals. The WAB is positioned adjacent to the back surface of the SDL,where the WAB is in signal communication with the back surface of theSDL and the WAB is configured to receive the plurality of focused RFsignals. The SAM in signal communication with the WAB and is configuredto electronically steer a beam of a radiation pattern produced by theSAA and switch between the plurality of focused RF signals based onelectronically steering the beam. The RAC is in signal communicationwith the SAM and is configured to produce a received RF signal from theplurality of focused RF signals.

The SAA may be part of a user terminal that includes an RF modem insignal communication with the SAA, where the RF modem is configured toreceive the RF signal and demodulate the received RF signal to produce areceived base-band signal, and a controller in signal communication withthe SAA and the RF modem. The controller is configured to control the RFmodem and the SAM to electronically steer the beam.

In an example of operation, the SAA performs a method that includesreceiving the plurality of incident RF signals at the front surface ofSDL and focusing the received plurality of incident RF signals to createthe plurality of focused RF signals at the plurality of focal pointsapproximately along the back surface of the SDL. The plurality of focalpoints have positions along the back surface of the SDL that correspondto the plurality of incident angles of the plurality of incident RFsignals. The method further includes receiving the plurality of focusedRF signals at the WAB positioned adjacent to the back surface of theSDL, switching between the plurality of focused RF signals based onelectronically steering the beam of the radiation pattern produced bythe SAA, and combining the switched plurality of focused RF signals toproduce the received RF signal with the RAC. Moreover, the SAA is areciprocal device capable of both receiving incident RF signals thatimping on the SDL and transmitting input RF signals that are in injectedinto the RAC. In the example of transmitting the input RF signals, theSAM is configured to electronically steer the transmitted beam.

Other devices, apparatus, systems, methods, features and advantages ofthe invention will be or will become apparent to one with skill in theart upon examination of the following figures and detailed description.It is intended that all such additional systems, methods, features andadvantages be included within this description, be within the scope ofthe invention, and be protected by the accompanying claims.

BRIEF DESCRIPTION OF THE FIGURES

The invention may be better understood by referring to the followingfigures. The components in the figures are not necessarily to scale,emphasis instead being placed upon illustrating the principles of theinvention. In the figures, like reference numerals designatecorresponding parts throughout the different views.

FIG. 1 is a system block diagram of an example of an implementation of aUAV user terminal in signal communication with a UAV, low-Earth-orbit(“LEO”) or geosynchronous satellite via a signal path in accordance withthe present disclosure.

FIG. 2 is a system block diagram of an example of an implementation ofthe user terminal shown in FIG. 1 in accordance with the presentdisclosure.

FIG. 3A is a top view of an example of an implementation of a cut-awayportion of a waveguide aperture block (“WAB”) shown in FIG. 2 inaccordance with the present disclosure.

FIG. 3B is a side cross-section view of the cut-away portion of the WABshown in FIG. 3A in accordance with the present disclosure.

FIG. 4 is a perspective view of an example of an implementation of aconformal aperture array antenna (“CAA”) shown in FIGS. 3A and 3B inaccordance with the present disclosure.

FIG. 5 is a perspective view of another example of an implementation ofthe CAA shown in FIGS. 3A and 3B in accordance with the presentdisclosure.

FIG. 6 is a system view of an example of an implementation of anapproximately spherical dielectric lens (“SDL”) shown in FIGS. 2, 3A,and 3B in accordance with the present disclosure.

FIG. 7A is a system view of another example implementation of the SDLreceiving an incident RF signal at a first angle in accordance with thepresent disclosure.

FIG. 7B is a system view of the SDL of FIG. 7A receiving an incident RFsignal at a second angle in accordance with the present disclosure.

FIG. 7C is a system view of the SDL of FIGS. 7A and 7B receiving anincident RF signal at a third angle in accordance with the presentdisclosure.

FIG. 8 is a perspective view of an example of an implementation of aradome for use with the SDL in accordance with the present disclosure.

FIG. 9 is a block diagram of an example of an implementation of awaveguide of the plurality of waveguides shown in FIGS. 3B, 6, 7A, 7B,and 7C in accordance with the present invention.

FIG. 10 is a block diagram of an example of an implementation of aswitch aperture matrix (“SAM”) shown in FIG. 2 in accordance with thepresent disclosure.

FIG. 11 is a block diagram of an example of an implementation of aradial aperture combiner (“RAC”) shown in FIG. 2 in accordance with thepresent disclosure.

FIG. 12 is a system block diagram of an example of an implementation ofa stepper motor for use with the WAB and SDL in accordance with thepresent disclosure.

FIG. 13 is a flowchart of an example of an implementation of a methodperformed by the SAA in accordance with the present disclosure.

DETAILED DESCRIPTION

A steerable antenna assembly (“SAA”) for receiving a plurality ofincident radio frequency (“RF”) signals at a plurality of incidentangles is disclosure. The SAA includes an approximately sphericaldielectric lens (“SDL”), a waveguide aperture block (“WAB”), a switchaperture matrix (“SAM”), and a radial aperture combiner (“RAC”). The SDLincludes a front surface and a back surface, where the SDL is configuredto receive and focus the plurality of incident RF signals to create aplurality of focused RF signals at a plurality of focal pointsapproximately along the back surface of the SDL. The plurality of focalpoints have positions along the back surface of the SDL that correspondto the plurality of incident angles of the plurality of incident RFsignals. The WAB is positioned adjacent to the back surface of the SDL,where the WAB is in signal communication with the back surface of theSDL and the WAB is configured to receive the plurality of focused RFsignals. The SAM in signal communication with the WAB and is configuredto electronically steer a beam of a radiation pattern produced by theSAA and switch between the plurality of focused RF signals based onelectronically steering the beam. The RAC is in signal communicationwith the SAM and is configured to produce a received RF signal from theplurality of focused RF signals.

The SAA may be part of a user terminal that includes an RF modem insignal communication with the SAA, where the RF modem is configured toreceive the RF signal and demodulate the received RF signal to produce areceived base-band signal, and a controller in signal communication withthe SAA and the RF modem. The controller is configured to control the RFmodem and the SAM to electronically steer the beam.

In an example of operation, the SAA performs a method that includesreceiving the plurality of incident RF signals at the front surface ofSDL and focusing the received plurality of incident RF signals to createthe plurality of focused RF signals at the plurality of focal pointsapproximately along the back surface of the SDL. The plurality of focalpoints have positions along the back surface of the SDL that correspondto the plurality of incident angles of the plurality of incident RFsignals. The method further includes receiving the plurality of focusedRF signals at the WAB positioned adjacent to the back surface of theSDL, switching between the plurality of focused RF signals based onelectronically steering the beam of the radiation pattern produced bythe SAA, and combining the switched plurality of focused RF signals toproduce the received RF signal with the RAC. Moreover, the SAA is areciprocal device capable of both receiving incident RF signals thatimping on the SDL and transmitting input RF signals that are in injectedinto the RAC. In receive mode the modem would demodulate the SAAreceived RF signal to produce a base-band signal. In transmit mode themodem would modulate an RF carrier for transmission through the SAA. Inboth transmit and receive modes a controller would be configured tosteer the SAA beam to the desired position.

In this disclosure, the SAA meets low cost, wide scan angle, fast scanrate, low re-pointing time, low sidelobe levels, low operating power andwide bandwidths needed for use in a UAV system or low-Earth orbiting(“LEO”) communication or geosynchronous satellites or via a directcommunication path to the UAV or satellite. The antenna system may alsobe used in a communications system, an aircraft (including the UAV), avehicle, a missile system, and many other beam forming applications.Additionally, the SAA may utilize additive and/or subtractive highvolume production manufacturing techniques for low cost fabrication ofthe SAA.

In FIG. 1, a system block diagram of an example of an implementation ofa user terminal 100 (which may be a UAV control and data system orsatellite terminal) in signal communication with a LEO or geosynchronoussatellite 102 (herein referred to as “satellite 102”) or a UAV 101 via asignal paths 104 or 105 is shown in accordance with the presentdisclosure. In this example, the user terminal 100 is shown as being onthe surface of the Earth 106 but it is appreciated by those of ordinaryskill in the art that the user terminal 100 may be instead be acommunication terminal (including non-satellite communicating devices)that is part of a communications system, a vehicle, an aircraft(including the UAV 101), or a missile system. In this example, the userterminal 100 in signal communication with the UAV 101 (via signal path105) or the satellite 102 (via signal path 104), where the Satellite 102is traveling in direction 108 that is along an orbital trajectory 110across a horizon 112 of the user terminal 100 and the UAV 101 istraveling in a direction 109 across the horizon 112. It is appreciatedby those of ordinary skill in the art that if the satellite 102 is a geostationary satellite (a special type of geosynchronous satellite with ageostationary orbit) it will not move along the orbital trajectory 110since it will be stationary with regards to the surface of the Earth106. It is also appreciated that instead of the user terminal 100 beingin signal communication with UAV 101 directly via signal path 105, theuser terminal 100 alternatively may be in signal communication with theUAV 101 via a combined signal path that includes signal path 104 to thesatellite 102, the satellite 102, and a signal path 113 to the UAV 101from the satellite 102. In this example, in order to maintaincommunication with either the UAV 101 along signal path 105 or thesatellite 102 along signal path 104, the user terminal 100 includesdevices, components, circuitry, etc. capable of producing an antennaradiation pattern having a beam 114 that is steerable 116 across thehorizon 112. As such, the user terminal 100 includes a SAA 118 andcommunication modem 120 in signal communication with the SAA 118. Inthis example, the beam 114 is a beam of an antenna radiation patternproduced by the SAA 118 that also includes a plurality of side-lobes122.

In FIG. 2, a system block diagram of an example of an implementation ofthe user terminal 100 (shown in FIG. 1) is shown in accordance with thepresent disclosure. In this example, the communication modem 120 mayinclude a radio frequency (“RF”) modem 200, controller 202, and powersupply 204. The controller 202 may be in signal communication with boththe RF modem 200 and power supply 204 via signal paths 206 and 208,respectively. The power supply 204 is also in signal communication withthe RF modem 200 via signal path 210. The RF modem 200 is also in signalcommunication with the SAA 118 via signal paths 212 and 214 and thecontroller 202 and power supply 204 are also in signal communicationwith the SAA 118 via signal paths 206 and 216, respectively.

The SAA 118 includes an approximately spherical dielectric lens (“SDL”)218, a waveguide aperture block (“WAB”) 220, a switch aperture matrix(“SAM”) 222, and a radial aperture combiner (“RAC”) 224. The SDL 218includes a front surface 226 and a back surface 228. In this example,the SDL 218 is configured to receive and focus a plurality of incidentRF signals 230 to create a plurality of focused RF signals at aplurality of focal points (not shown) approximately along the backsurface 228 of the SDL 218 and where the plurality of focal points havepositions along the back surface 228 of the SDL 228 that correspond tothe plurality of incident angles θ 232 of the plurality of incident RFsignals 230. In this example, the SAM 222 is in signal communicationwith the controller 202 and the power supply 204 via signal paths 206and 216, respectively. Additionally, the RAC 224 includes a first andsecond waveguide input-output (“IO”) ports 234 and 236, where both thefirst and second waveguide IO ports 234 and 236 are configured to be“output” ports (i.e., they produce output signals) when the SAA 118 isreceiving an incident RF signal (of the plurality of incident RF signals230) and, when the SAA 118 is transmitting a transmitted RF signal, thefirst and second waveguide IO ports 234 and 236 are configured to be“input” ports (i.e., they receive input signals) and receive an input RFsignal from the RF modem 200.

In this example, the SDL 218 has a shape that is approximately a sphereor an oblate spheroid with a sphericity variation that is less thanapproximately 0.01 wavelength of an operating RF frequency of the SAA118, where the operating frequency of the SAA 118 may be in a range, forexample, of approximately between K-band to W-band (i.e., fromapproximately 18 GHz to 110 GHz). It is appreciated by those of ordinaryskill in the art that lower frequencies may also be utilized but thiswould result in the SDL 218 having a larger diameter. In the case ofK-band, the SDL 218 may have a diameter of, for example, approximately152.4 mm that is scalable based on the designed frequency of operationof the SAA 118. Additionally, the SDL may have a dielectric constantthat is constant or varying between approximately 2 and 5 for providinga loss tangent of less than about 0.001. It is appreciated by those ofordinary skill in the art that the dielectric constant is the ratio ofthe permittivity of a substance to the permittivity of free space andthat it is an expression of the extent to which a material concentrateselectric flux such that as the dielectric constant increases, theelectric flux density increases.

Moreover, the SDL 218 may have a gradient of decreasing refractive indexradially out from a center (shown in FIG. 6 as 604) of the SDL 218. Assuch, the SDL may be, for example, a Luneburg lens, where the Luneburglens is a spherical lens generally having a gradient of decreasingrefractive index radially out from its center and where the focusingproperties may be achieved through an infinite number ofrefractive-index solutions.

In general, the SDL 218 may be constructed of materials that include,for example, a thermoset plastic, a polycarbonate, a cross-linkedpolystyrene copolymer, and Polytetrafluoroethylene (“PTFE”). As such,example materials include REXOLITE® and TEFLON®. REXOLITE® 1422 ismanufactured by C-Lec Plastics, Inc. of Philadelphia, Pa. and may beavailable as a dielectric lens from San Diego Plastics, Inc. of NationalCity, Calif., or elsewhere. TEFLON® is available from The ChemoursCompany of Wilmington, Del., and may be available as a dielectric lensfrom Applied Plastics Technology, Inc. of Bristol, R.I., or elsewhere.In this example, the SDL 218 may be formed by injection molding or someother process (e.g. 3-D printing or additive manufacturing). In thisexample, the SAA 118 may optionally include a radome (shown in FIG. 8 as800) disposed adjacent to the front surface 226 of the SDL 218.

Turning to the WAB 220, the WAB 220 is a device, component, or modulethat includes a concave inner surface 238 positioned adjacent to theback surface 228 of the SDL 218 and a conformal aperture array antenna(“CAA”) (shown as 304 in FIGS. 3A and 3B) along the concave innersurface 238. In this example, the CAA 304 is in signal communicationwith the back surface 228 of the SDL 218 and includes a plurality ofaperture elements (shown in FIGS. 3A and 3B as 306(1), 306(2), 306(3),306(4), 306(5), 306(6), and 306(7)). In this example, the back surface228 of the SDL 218 is ideally flush with the concave inner surface 238so as to minimize any space between back surface 228 of the SDL 218 andthe concave inner surface 238 because any spacing between the backsurface 228 and concave inner surface 238 will produce an impedancemismatch that will result in RF reflections between the back surface 228and concave inner surface 238. This impedance mismatch will result inlosses and will increase the side-lobes 122 of the radiation pattern ofthe SAA 118 and resulting reduce the gain and directivity of the SAA118. However, it is appreciated that based on the utilization of somematerials for the SDL 218, there may alternatively be situations wherethe design will include a small spacing between the back surface 228 andconcave inner surface 238 and the SDL 218 to properly match the SDL 218and concave inner surface 238.

In this example, the WAB 220 includes a plurality of waveguides (shownin FIG. 3B as 312) in signal communication with the CAA 304, where eachwaveguide (shown in FIG. 3B as 314(1), 314(2), 314(3), 314(4), 314(5),314(6), and 314(7)), of the plurality of waveguides, includes awaveguide aperture (shown in FIGS. 3A and 3B as 306(1), 306(2), 306(3),306(4), 306(5), 306(6), and 306(7) as aperture elements) in signalcommunication with the CAA 304. Each waveguide aperture, of eachwaveguide of the plurality of waveguides, corresponds to an apertureelement 306(1), 306(2), 306(3), 306(4), 306(5), 306(6), and 306(7) ofthe plurality of aperture elements of the CAA 304. As an example, theWAB is constructed of metal or metalized plastics.

The SAM 222 is a device, component, circuit, or module that includes aplurality of selectively activated switches (shown in FIG. 10 as1000(1), 1000(2), 1000(3), and 1000(N)), where each selectivelyactivated switch, of the plurality of selectively activated switches, isin signal communication with a corresponding waveguide from theplurality of waveguides (shown in FIG. 3B as 312) of the WAB 220 and theRAC 224. In this example, each selectively activated switch isconfigured to conduct or block a waveguide output signal from thecorresponding waveguide output port to the RAC 224 if the SAA 118 isoperating in a receiving mode. If, instead, the SAA 118 is operating ina transmitting mode, each selectively activated switch is configured toconduct or block an input RF signal from the RAC 224 to eachcorresponding waveguide input port. In this example, it is appreciatedby those of ordinary skill in the art that these waveguide ports arereferred to as “waveguide output ports” if the SAA 118 is an receivingmode and the waveguide ports are producing output RF signalscorresponding to the received incident RF signals 230. Alternatively,the same waveguide ports are referred to as “waveguide input ports” ifthe SAA 118 is in transmitting mode and the waveguide ports arereceiving input RF signals corresponding from the RAC 224. In thisexample, each selectively activated switch includes a switching device(not shown) that may be, for example, a PIN diode, latching ferriteswitch, liquid crystal valve (“LCV”), coaxial waveguide switch, plasmaswitch, and an RF isolator.

The RAC 224 is a device, component, circuit, or module that isconfigured to receive the switched outputs (not shown) from the SAM 222and combine them routes them to the IO ports 234 and 236 in thereceiving mode. As an example, the RAC 224 may be a radial powercombiner and divider utilizing waveguide, coaxial transmission lines, orsolid-state technologies (e.g., striplines or microstrips). In thetransmitting mode, the RAC 224 receives an input RF signal (not shown)and routes it to one of more selectively activated switches in the SAM222. In this example, two IO ports 234 are 236 are shown to produce orreceive polarized RF signals that are routed to or from the RF modem 200via signal paths 212 and 214, respectively. For example, first IO port234 is shown to produce a first polarized output signal 240 that ispassed from the RAC 224 to the RF modem 200 in a receive mode and, in atransmit mode, to receive a first polarized input signal 242 from the RFmodem 200 to the RAC 224. Similarly, the second IO port 236 is shown toproduce a second polarized output signal 244 that is passed from the RAC224 to the RF modem 200 in a receive mode and, in a transmit mode, toreceive a second polarized input signal 246 from the RF modem 200 to theRAC 224. In this example, the first polarization may be left-handcircular polarization (“LHCP”) and the second polarization may beright-hand circular polarization (“RHCP”). It is appreciated by those ofordinary skill in the art that two IO ports 234 are 236 may include asingle waveguide IO port having a polarizer such as, for example, aseptum polarizer.

In this example, the RF modem 200 is a device, component, circuit, ormodule that is configured to receive either the first polarized outputsignal 240 or second polarized output signal 244 and then demodulateeither one to produce a received base-band signal 248 that is passed tothe controller 202 via signal path 206. The controller 202 then mayreceive the base-band signal 248 to produce data 250 that is output fromthe controller 202 to other devices, components, circuits, or modules ofthe user terminal 100. The data 250 may also be routed to other externaldevices in signal communication with the user terminal 100 viaconnections such as, for example, an Ethernet connection. In thisexample, the RF modem 200 is also configured to receive an inputbased-band signal 252 from the controller 202 and then modulate theinput based-band signal 252 to produce either the second polarizedoutput signal 244 or the second polarized input signal 246 that arerouted to the IO ports 234 and 236, respectively.

The controller 202 is a device, component, circuit, or module thatincludes a processor, digital signal processor (“DSP”), applicationspecific integrated circuit (“ASIC”), field programmable gate array(“FPGA”), or equivalent. The controller 202 produces control logicsignals 254 that are passed and received from the RF modem 200 and SAM222. The control logic signals 254 provide synchronized control signalsto both the SAM 222 and RF modem 200 to selectively receive anddemodulate input RF signals (such as, for example first polarized outputsignal 240 or second polarized output signal 244) or selectivelymodulate and transmit RF signals (such as, for example, second polarizedinput signal 242 or second polarized input signal 246) through the SAA118. In this example, by controlling the selectively activated switcheswithin the SAM 222 with the control logic signals 254, the controller202 is configured to electronically steer the beam 114 with the SAM 222.

The power supply 204 is a device, component, circuit, or module that isconfigured to receive external power 256 and produce the appropriatepower signals for the SAM 222, controller 202, and RF modem 200 viasignal path 216, 208, and 210, respectively. The SAA 118 may alsoinclude stepper motor (shown in FIG. 12 as 1200) that is configured toselectively rotate the WAB 220 and SDL 218 based on a control signal(shown in FIG. 12 as 1204) from the controller 202.

It is appreciated by those skilled in the art that the circuits,components, modules, and/or devices of, or associated with, the userterminal 100, SAA 118, and communication modem 120 are described asbeing in signal communication with each other, where signalcommunication refers to any type of communication and/or connectionbetween the circuits, components, modules, and/or devices that allows acircuit, component, module, and/or device to pass and/or receive signalsand/or information from another circuit, component, module, and/ordevice. The communication and/or connection may be along any signal pathbetween the circuits, components, modules, and/or devices that allowssignals and/or information to pass from one circuit, component, module,and/or device to another and includes wireless or wired signal paths.The signal paths may be physical, such as, for example, conductivewires, electromagnetic wave guides, cables, attached and/orelectromagnetic or mechanically coupled terminals, semi-conductive ordielectric materials or devices, or other similar physical connectionsor couplings. Additionally, signal paths may be non-physical such asfree-space (in the case of electromagnetic propagation) or informationpaths through digital components where communication information ispassed from one circuit, component, module, and/or device to another invarying digital formats without passing through a direct electromagneticconnection.

In an example of operation, the SAA 118 performs a method that includesreceiving the plurality of incident RF signals 230 at a front surface226 of the SDL 218 and focusing the received plurality of incident RFsignals 230 to create a plurality of focused RF signals at a pluralityof focal points approximately along the back surface 228 of the SDL 218,where the plurality of focal points have positions along the backsurface 228 of the SDL 218 that correspond to the plurality of incidentangles 232 of the plurality of incident RF signals 230. The method alsoincludes receiving the plurality of focused RF signals at the WAB 220that is positioned adjacent to the back surface 228 of the SDL 218 andswitching between the pluralities of focused RF signals based onelectronically steering the beam 114 of the radiation pattern producedby the SAA 118. Moreover, the method includes combining the switchedplurality of focused RF signals (not shown) to produce the received RFsignal (i.e., LHCP 240 and RHCP 244) with the RAC 224. In this example,the switching conducting or blocking a plurality of output signals, fromthe corresponding plurality of waveguide output ports, from the WAB 220to the RAC 224. The method may also include rotating the WAB 220 and SDL218 with the stepper motor 1200 based on the control signal 1204 fromthe controller 202.

In FIG. 3A, a top view of an example of an implementation of a cut-awayportion of the WAB 220 is shown in accordance with the presentdisclosure. In this example, the WAB 220 includes the concave innersurface 238, an outside surface 300 of the WAB 220, and a lip 302between the concave inner surface 238 and the outside surface 300. Thelip 302 may have a thickness that is wide enough to allow a mountingflange (not shown) for the SDL 218. If a mounting flange (not shown) isutilized, the lip 302 may include a plurality of down pin holes (notshown) and screw holes (not shown) to line up and attaching the mountingflange (not shown) to the lip 302. In this example, the concave innersurface 238 includes the CAA 304, where the CAA 304 includes a pluralityof aperture elements 306(1), 306(2), 306(3), 306(4), 306(5), 306(6), and306(7). In this example, each aperture element 306(1), 306(2), 306(3),306(4), 306(5), 306(6), and 306(7) is a waveguide aperture (i.e., anopening of the waveguide that will allow the reception or transmissionof RF signals into or out of the waveguide). In general, the CAA 304 is“bowl” shaped composed of either solid metal and/or metalized plastic.It is a reciprocal device capable of simultaneously transmitting andreceiving RF signals within the selected directions of arrival (i.e.,the plurality of incident angles 232) and will minimize RF insertion andpolarization losses.

Turing to FIG. 3B, a side cross-section view of the cut-away portion 308of the WAB 220 is shown in accordance with the present disclosure.Specifically, FIG. 3B is a cross-sectional view of the cut-way portion308 of the WAB 220 along cutting plane A-A′ 310 looking into the WAB220. As discussed earlier, the WAB 220 includes a plurality ofwaveguides 312 in signal communication with the CAA 304, where eachwaveguide 314(1), 314(2), 314(3), 314(4), 314(5), 314(6), and 314(7), ofthe plurality of waveguides 312, includes a waveguide aperture (which inthis example corresponds to the aperture element 306(1), 306(2), 306(3),306(4), 306(5), 306(6), and 306(7)) in signal communication with the CAA304. It is appreciated by those of ordinary skill in the art that inthis example each waveguide aperture 306(1), 306(2), 306(3), 306(4),306(5), 306(6), and 306(7), of each waveguide 314(1), 314(2), 314(3),314(4), 314(5), 314(6), and 314(7) of the plurality of waveguides 312,corresponds to an aperture element 306(1), 306(2), 306(3), 306(4),306(5), 306(6), and 306(7) of the plurality of aperture elements of theCAA 304 because each waveguide aperture 306(1), 306(2), 306(3), 306(4),306(5), 306(6), and 306(7) is by definition a radiating element 306(1),306(2), 306(3), 306(4), 306(5), 306(6), and 306(7). In this example, theWAB 220 and each waveguide 314(1), 314(2), 314(3), 314(4), 314(5),314(6), and 314(7) may be constructed of metal or metalized plastics.

Also as discussed earlier, in this example, the back surface 228 of theSDL 218 is ideally flush with the concave inner surface 238 so as tominimize any space between back surface 228 of the SDL 218 and theconcave inner surface 238 because any spacing between the back surface228 and concave inner surface 238 will produce an impedance mismatchthat will result in RF reflections between the back surface 228 andconcave inner surface 238. It is appreciated that any space between theback surface 228 and concave inner surface 238 will act as a dielectriclayer (with a dielectric constant of approximately 1.00059 at 25° C.)between the dielectric material of the SDL 218 at the back surface 228and the openings of each waveguide aperture causing reflections at thespacing layer (back into the SDL 218 and/or the 306(1), 306(2), 306(3),306(4), 306(5), 306(6), and 306(7)) based on the wavelengths of RFsignals within the frequency of operation. Additionally, based on thewavelengths of RF signals within the frequency of operation, the spacinglayer may allow power dissipation along the surfaces of the both theback surface 228 of the SDL 218 and the concave inner surface 238causing power loss and potential cross-talk between the differentwaveguide apertures 306(1), 306(2), 306(3), 306(4), 306(5), 306(6), and306(7). These effects will cause the impedance mismatch that will resultin losses and will increase the side-lobes 122 of the radiation patternof the SAA 118 and resulting reduce the gain and directivity of the SAA118.

In this example, each aperture element 306(1), 306(2), 306(3), 306(4),306(5), 306(6), and 306(7) of the CAA 304 may be an elliptical aperture,where, correspondingly, each waveguide aperture 306(1), 306(2), 306(3),306(4), 306(5), 306(6), and 306(7) of the each waveguide 314(1), 314(2),314(3), 314(4), 314(5), 314(6), and 314(7) of the plurality ofwaveguides 312 is an elliptical aperture. Alternatively, each apertureelement may be rectangular but in the case of elliptically polarizedincident RF signals 230 or transmitted RF signals 230, the resultingfocal points of the SDL 218 tend to be elliptical, or even circular, inshape. Since most communication systems utilizing ellipticalpolarization actually utilize either LHCP or RHCP, the aperture elements306(1), 306(2), 306(3), 306(4), 306(5), 306(6), and 306(7) andcorresponding waveguide apertures 306(1), 306(2), 306(3), 306(4),306(5), 306(6), and 306(7) may be circular. Additionally, for ease offabrication purposes, each circular aperture element 306(1), 306(2),306(3), 306(4), 306(5), 306(6), and 306(7) may be three-dimensionallyprinted or drilled out of the concave inner surface 238. In thisexample, it is appreciated by those of ordinary skill in the art thatthe circularly shaped waveguide apertures may operate with a dominanttransverse electromagnetic mode that is TE₁₁ mode.

In this example, all of the waveguides 314(1), 314(2), 314(3), 314(4),314(5), 314(6), and 314(7) of the plurality of waveguides 312 include afirst port and a second port where each first port corresponds to eachwaveguide aperture 306(1), 306(2), 306(3), 306(4), 306(5), 306(6), and306(7) and the second port corresponds to the IO port 316(1), 316(2),316(3), 316(4), 316(5), 316(6), and 316(7) that is in signalcommunication with the SAM 222.

In the case of circularly shaped aperture elements 306(1), 306(2),306(3), 306(4), 306(5), 306(6), and 306(7), each waveguide 314(1),314(2), 314(3), 314(4), 314(5), 314(6), and 314(7) will need to beeither partially or completely a circular waveguide (i.e., circularlyshaped) based on the design of the WAB 220, SAM 222, and RAC 224. Inthis example, the plurality of waveguides 312 includes a sub-pluralityof waveguides that includes 314(1), 314(2), 314(3), 314(5), 314(6), and314(7), where the each waveguide 314(1), 314(2), 314(3), 314(5), 314(6),and 314(7) of the sub-plurality of waveguides includes a waveguidelength (shown in FIG. 9 as 900), a waveguide directional transition(shown in FIG. 9 as bend 904), and optionally a waveguide transition(shown in FIG. 9 as circular-to-rectangular transition 906) from thecircular aperture 306(1), 306(2), 306(3), 306(5), 306(6), and 306(7) toa rectangular waveguide. In this example, the middle waveguide 314(4)having the waveguide aperture 306(4) includes a waveguide length andoptionally a waveguide transition from the circular aperture 306(4) to arectangular waveguide but does not need a waveguide directionaltransition since it is shown as being a straight waveguide in thisexample.

In this example, the SAM 222 and RAC 224 will operate with rectangularwaveguides that have a dominant transverse electromagnetic mode that isTE₁₀ mode. In order to pass RF signals from or to the circular waveguideapertures 306(1), 306(2), 306(3), 306(4), 306(5), 306(6), and 306(7)from or to a rectangular waveguide, each waveguides 314(1), 314(2),314(3), 314(4), 314(5), 314(6), and 314(7) needs acircular-to-rectangular waveguide transition (generally known as a modetransition) which are generally well known by those of ordinary skill inthe art.

Moreover, in this example, each waveguide aperture 306(1), 306(2),306(3), 306(4), 306(5), 306(6), and 306(7) is aligned with the center604 of the SDL 218 and each waveguide IO port 316(1), 316(2), 316(3),316(4), 316(5), 316(6), and 316(7) is aligned the other waveguide outputports 316(1), 316(2), 316(3), 316(4), 316(5), 316(6), and 316(7) along aplane of alignment 318 where the WAB 220 is connected to the SAM 222.Furthermore, each IO port 316(1), 316(2), 316(3), 316(4), 316(5),316(6), and 316(7) is in signal communication with the SAM 222.

In this example, each waveguide 314(1), 314(2), 314(3), 314(5), 314(6),and 314(7) of the sub-plurality of waveguides 312 has a directionaltranslation that bends (i.e., changes the direction) the waveguide314(1), 314(2), 314(3), 314(5), 314(6), and 314(7) so that eachwaveguide aperture 306(1), 306(2), 306(3), 306(4), 306(5), 306(6), and306(7) is aligned (i.e., is directed to) with the center 604 of the SDL218 and the IO ports 316(1), 316(2), 316(3), 316(4), 316(5), 316(6), and316(7) are aligned with the plane of alignment 318. As an example, thebends may be either H-bends (i.e., a bend that distorts the magneticfield) or E-bends (i.e., a bend that distorts the electric field) forrectangular waveguides or E-bends for circular waveguides.

As an example of an alternative implementation, the plurality ofwaveguides 312 may include different types of transmission lines thatinclude waveguides, coaxial transmission lines, solid-state waveguides,hybrid transmission lines of waveguides and solid-state waveguides,hybrid transmission lines of coaxial and waveguides, hybrid transmissionlines of coaxial and solid-states waveguides or any other combinationcapable of transmitting RF signals at the frequency of operation. Inthis disclosure, solid-state waveguides include microstrip or striplinecircuits. In the case of solid-state waveguides, the waveguide aperturesmay be implemented as utilizing microstrip antennas fabricated usingmicrostrip techniques on a printed circuit board (“PCB”). As an example,the microstrip antenna may be implemented as a patch antenna.

In this example, only seven (7) aperture elements of the CAA 304 andwaveguides 314(1), 314(2), 314(3), 314(5), 314(6), and 314(7) are shown.This is for purposes of ease of illustration and it is appreciated by ofordinary skill in the art the CAA 304 may include many more radiatingelements that may be distributed in a conformal fashion along the entireconcave inner surface 238 of the CAA 304. Likewise, the plurality ofwaveguides 312 may include many more waveguides three-dimensionallywithin the WAB 220, where each waveguide corresponds to each radiatingelements of the CAA 304.

Turning to FIG. 4, a perspective view of an example of an implementationof a CAA 304 is shown in accordance with the present disclosure. Thisexample is similar to the one shown in FIGS. 3A and 3B except that theCAA 304 for illustration purposes was shown having seven (7) apertureelements, while in this example the CAA 304 is shown having eighty-five(85) aperture elements. Similarly, in FIG. 5, a perspective view ofanother example of an implementation of the CAA 304 is shown, inaccordance with the present disclosure, where the CAA 304 includes, forexample, 1,112 aperture elements.

In FIG. 6, a system view of an example of an implementation of SDL 218is shown in accordance with the present invention. In this example,incident RF signals 230 are shown as plurality of individual incident RFsignals 600(1), 600(2), 600(3), 600(4), 600(5), 600(6), and 600(7)arriving at the SDL 218 from incident different angles 232. Again forthe purposes of ease of illustration, only seven (7) individual incidentRF signals are shown but it is appreciated that there may be many moreindividual incident RF signals that imping on the front surface 226 ofthe SDL 218. In an example of operation, when the individual incident RFsignals 600(1), 600(2), 600(3), 600(4), 600(5), 600(6), and 600(7)imping on the front surface 226 of the SDL 218 then travel throughdielectric of the SDL 218 and focus on to the corresponding focal points602(1), 602(2), 602(3), 602(4), 602(5), 602(6), and 602(7),respectively. In this example for ease of illustration the individualincident RF signals 600(1), 600(2), 600(3), 600(4), 600(5), 600(6), and600(7) are shown traveling through the center 604 of the SDL 218 willtraveling to the corresponding focal points 602(1), 602(2), 602(3),602(4), 602(5), 602(6), and 602(7), however it is appreciated that thepurpose of the illustration is to show that any individual incident RFsignals 600(1), 600(2), 600(3), 600(4), 600(5), 600(6), and 600(7)impinging the front surface 226 of the SDL 218 will be focused at afocal point located approximately on the back surface 228 of the SDL 218that is at the opposite side of the point where the individual incidentRF signal impinged on the front surface 226 of the SDL 218. In thisexample, the focal points 602(1), 602(2), and 602(3) would correspond tothe individual incident RF signals 600(7), 600(6), and 600(5) impingingthe front surface 226 of the SDL 218 at impinging points 606(1), 606(2),and 606(4), respectively. The focal point 602(4) would correspond to theindividual incident RF signal 600(4) impinging the front surface 226 ofthe SDL 218 at impinging point 606(4). Moreover, the focal points602(5), 602(6), and 602(7) would correspond to the individual incidentRF signals 600(3), 600(2), and 600(1) impinging the front surface 226 ofthe SDL 218 at impinging points 606(5), 606(6), and 606(7),respectively. In this example, the focal points 602(1), 602(2), 602(3),602(4), 602(5), 602(6), and 602(7) correspond to the waveguides 314(1),314(2), 314(3), 314(5), 314(6), and 314(7), respectively. Additionally,for purposes of illustration the front surface 226 of the SDL 218 isshown to be the surface of a front hemisphere of the SDL 218 and theback surface 228 of the SDL 218 is shown to be a surface of a backhemisphere of the SDL 218 that is designated by a hemispherical divisionplane 608. Utilizing this approach the SDL 218 is capable of wide scans(up to approximately ±60 degrees or more) in both azimuth and elevation.

In FIG. 7A, a system view of another example implementation of the SDL218 receiving an incident RF signal 700 at a first angle is shown inaccordance with the present disclosure. In this example, the incident RFsignal 700 is a RF signal from the incident RF signals 230 and the SDL218 is a Lundeberg type lens having a gradient of decreasing refractiveindex radially out from the center 604. In this example, the SDL 218 hasan index of refraction of one (1) at the surface and an index ofrefraction equal to the square root of two (2) (i.e., approximately1.414) at the center 604.

In this example, as the distance from the center 604 of a SDL 218 isincreased, the index of refraction gradually decreases. The geometry andrefractive properties of the SDL 218 causes the incident RF signal 700to travel to a location on the opposite side of the SDL 218 at the focalpoint 602(6) and exit the SDL 218 to the waveguide 314(6). In thisexample, an incident plane wave of the incident RF signal 700 may berepresented by a plurality of parallel waves of radiation 702(1),702(2), 702(3), 702(4), 702(5), 702(6), and 702(7) impinging on thefront surface 226 of the SDL 218. As such, the wave 702(1) that impingesthe front surface 226 at a normal passes through the center 604 of theSDL 218 along a centerline of the SDL 218 and exits at focal point602(6) on the opposite side of the back surface 228 of the SDL 218. Theother incident parallel waves of radiation, represented by lines 702(2),702(3), 702(4), 702(5), 702(6) and 702(7), imping the SDL 218 at variouslocations along the front surface 226 of the SDL 218 and travel throughthe SDL 218 in paths dictated by the geometric and refractive propertiesof the SDL 218 so as to arrive at the same exit location at focal point602(6). As such, in this example the SDL 218 focuses the most of theenergy from the incident RF signal 700 to the focal point 602(6) andpasses it to the waveguide 314(6).

Similarly, in FIG. 7B, a system view of the SDL 218 of FIG. 7A is shownreceiving an incident RF signal 704 at a second angle in accordance withthe present disclosure. In this example, the incident plane wave of theincident RF signal 704 is represented by a plurality of parallel wavesof radiation 706(1), 706(2), 706(3), 706(4), 706(5), 706(6), and 706(7)impinging on the front surface 226 of the SDL 218. As such, the wave706(1) that impinges the front surface 226 at a normal passes throughthe center 604 of the SDL 218 along a centerline of the SDL 218 andexits at focal point 602(4) on the opposite side of the back surface 228of the SDL 218. The other incident parallel waves of radiation,represented by lines 706(2), 706(3), 706(4), 706(5), 706(6) and 706(7),imping the SDL 218 at various locations along the front surface 226 ofthe SDL 218 and travel through the SDL 218 in paths dictated by thegeometric and refractive properties of the SDL 218 so as to arrive atthe same exit location at focal point 602(4). As such, in this examplethe SDL 218 focuses the most of the energy from the incident RF signal704 to the focal point 602(4) and passes it to the waveguide 314(4).

Turning to FIG. 7C, a system view of the SDL 218 of FIGS. 7A and 7B isshown receiving an incident RF signal 708 at a third angle in accordancewith the present disclosure. Similar to the examples in FIGS. 7A and 7B,in this example, the incident plane wave of the incident RF signal 708is represented by a plurality of parallel waves of radiation 710(1),710(2), 710(3), 710(4), 710(5), 710(6), and 710(7) impinging on thefront surface 226 of the SDL 218. As such, the wave 710(1) that impingesthe front surface 226 at a normal passes through the center 604 of theSDL 218 along a centerline of the SDL 218 and exits at focal point602(2) on the opposite side of the back surface 228 of the SDL 218. Theother incident parallel waves of radiation, represented by lines 710(2),710(3), 710(4), 710(5), 710(6) and 710(7), imping the SDL 218 at variouslocations along the front surface 226 of the SDL 218 and travel throughthe SDL 218 in paths dictated by the geometric and refractive propertiesof the SDL 218 so as to arrive at the same exit location at focal point602(2). As such, in this example the SDL 218 focuses the most of theenergy from the incident RF signal 708 to the focal point 602(2) andpasses it to the waveguide 314(2). In these examples, the transmittedsignals at the focal points 602(6), 602(4), and 602(2) are the focusedRF signals of the corresponding incident RF signals 700, 704, and 708,respectively.

FIG. 8 is a perspective view of an example of an implementation of aradome 800 for optional use with the SDL 218 in accordance with thepresent disclosure. The radome 800 may include a radome flange 802 thatmay be attached to the lip 302 of the WAB 220 via pin and screw holes804 that line up and attach the radome 800 to the lip 302 or to amounting flange (not shown) of the SDL 218. In this example, the radome800 may be composed of an electrically transparent material and disposedadjacent to the SDL 218 to protect the front surface 226 of the SDL 218from damage and/or environmental conditions.

In FIG. 9, a block diagram of an example of an implementation of awaveguide of the plurality of waveguides 312 is shown in accordance withthe present invention. In this example, the waveguide is waveguide314(1) and has a waveguide length 900. The waveguide 314(1) includes thecircular aperture 306(1) that is aligned towards the center 604 of theSDL 218, a circular waveguide portion 902, a waveguide directionaltransition (i.e., bend 904), a waveguide transition from a circularaperture to a rectangular waveguide (i.e., circular-to-rectangularwaveguide transition 906), a rectangular waveguide 908, and the IO port316(1). As stated earlier, the bend 904 may be either H-bends (i.e., abend that distorts the magnetic field) or E-bends (i.e., a bend thatdistorts the electric field) for rectangular waveguide. Also, since thewaveguide 314(1) includes the circular aperture 306(1) and the circularwaveguide 902 portion, this portion of the waveguide 314(1) willgenerally operate with the TE₁₁ mode, which is the dominant mode for acircular waveguide. The circular-to-rectangular waveguide transition 906will change another portion of the waveguide 314(1) to the rectangularwaveguide 908, which will generally operate with the TE₁₀ mode, which isthe dominant mode for a rectangular waveguide. The IO port 316(1)couples the waveguide 314(1) to the SAM 222.

In FIG. 10, a block diagram of an example of an implementation of theSAM 222 is shown in accordance with the present disclosure. As discussedearlier, the SAM 222 is a device, component, circuit, or module thatincludes a plurality of selectively activated switches 1000(1), 1000(2),1000(3), and 1000(N) where each selectively activated switch, of theplurality of selectively activated switches 1000(1), 1000(2), 1000(3),and 1000(N), is in signal communication with a corresponding waveguidefrom the plurality of waveguides 312 of the WAB 220 and the RAC 224. Inthis example, only four (4) selectively activated switches 1000(1),1000(2), 1000(3), and 1000(N) are shown for the purpose of ease ofillustration, however there may be up to N selectively activatedswitches where N corresponds to the number of waveguides in theplurality of waveguides 312 of the WAB 220 and the number of IO ports(not shown) at the RAC 224.

In this example, each selectively activated switch 1000(1), 1000(2),1000(3), and 1000(N) is configured to conduct or block a waveguideoutput signal 1002 from the corresponding waveguide IO port (such as316(1), 316(2), 316(3), 316(4), 316(5), 316(6), and 316(7) in theexample of FIG. 3B) of the plurality of waveguides 312 to the RAC 224 ifthe SAA 118 is operating in a receiving mode. If, instead, the SAA 118is operating in a transmitting mode, each selectively activated switch1000(1), 1000(2), 1000(3), and 1000(N) is configured to conduct or blockan input RF signal 1004 from the RAC 224 to each corresponding waveguideIO port. In this example, the selectively activated switches 1000(1),1000(2), 1000(3), and 1000(N) may be waveguide switches. Again, in thisexample, each selectively activated switch includes a switching device(not shown) that may be, for example, a PIN diode, latching ferriteswitch, LCV, coaxial waveguide switch, and an RF isolator.

Turing to FIG. 11, a block diagram of an example of an implementation ofthe RAC 224 is shown in accordance with the present disclosure. Asdiscussed earlier, the RAC 224 is a device, component, circuit, ormodule that is configured to receive the switched outputs 1100 from theSAM 222 and combine them routes them to the IO ports 234 and 236 in thereceiving mode. As an example, the RAC 224 may be a radial powercombiner and divider utilizing waveguide, coaxial transmission lines, orsolid-state technologies (e.g., striplines or microstrips). In thetransmitting mode, the RAC 224 receives an input RF signal (either inputRF signals 242 or 246) and routes it to one of more selectivelyactivated switches 1000(1), 1000(2), 1000(3), and 1000(N) in the SAM222. In this example, two IO ports 234 are 236 are shown to produce orreceive polarized RF signals that are routed to or from the RF modem 200via signal paths 212 and 214, respectively. For example, first IO port234 is shown to produce the first polarized output signal 240 that ispassed from the RAC 224 to the RF modem 200 in a receive mode and, in atransmit mode, to receive the first polarized input signal 242 from theRF modem 200 to the RAC 224. Similarly, the second IO port 236 is shownto produce the second polarized output signal 244 that is passed fromthe RAC 224 to the RF modem 200 in a receive mode and, in a transmitmode, to receive the second polarized input signal 246 from the RF modem200 to the RAC 224. Again, in this example, the first polarization maybe LHCP and the second polarization may be right-hand circularpolarization RHCP. It is appreciated by those of ordinary skill in theart that two IO ports 234 are 236 may include a single waveguide IO porthaving a polarizer such as, for example, a septum polarizer 1102.

In FIG. 12, a system block diagram of an example of an implementation ofthe stepper motor 1200 for use with the WAB 220 and SDL 218 is shown inaccordance with the present disclosure. As discussed earlier, the SAA118 may also include the stepper motor 1200 that is configured toselectively rotate the WAB 220 and SDL 218 based on a control signal1204 from the controller 202. In this example, the stepper motor 1200 isoperatively coupled to the WAB 220 and/or the SDL 218. A reason forincluding the stepper motor 1200 in the SAA 118 is that it is possiblethat the orientation of a particular transceiver relative to thecombination of SDL 218 and WAB 220 is inaccurate or not correctlyaligned. To address this possible orientation issue, the stepper motor1200 may be mechanically linked 1206 to WAB 220 and/or SDL 218 to eitherrotate the WAB 220 or SDL 218 in reference to transceiver located atdistant points and oriented at a direction of arrival 206 and directionof departure 218. By rotating WAB 220, different transceivers may beacquired by the SDL 218 that may not be in optimal alignment with thewaveguides of WAB 220 based on fixed beam-to-beam spacing.

FIG. 13 is a flowchart 1300 of an example of an implementation of amethod performed by the SAA 118 in accordance with the presentdisclosure. The method starts by receiving the plurality of incident RFsignals 230 at a front surface 226 of an SDL 218, in step 1302, andfocusing the received plurality of incident RF signals 230 to create aplurality of focused RF signals at a plurality of focal pointsapproximately along the back surface 228 of the SDL 218 in step 1304. Inthis example, the plurality of focal points have positions along theback surface 228 of the SDL 218 that correspond to the plurality ofincident angles 232 of the plurality of incident RF signals 230. Themethod further includes receiving the plurality of focused RF signals atthe WAB 220 positioned adjacent to the back surface 228 of the SDL 218,in step 1306, and switching between the pluralities of focused RFsignals based on electronically steering the beam 114 of the radiationpattern produced by the SAA 118 in step 1308. The method then includescombining the switched plurality of focused RF signals to produce areceived RF signal with RAC 224 in step 1310. The method then ends.

The disclosure presented herein may be considered in view of thefollowing clauses.

Clause A, a SAA (118) for receiving a plurality of incident RF signals(230) at a plurality of incident angles (232), the SAA (118) comprising:an approximately SDL (218) having a front surface (226) and a backsurface (228), the SDL being operable to receive and focus the pluralityof incident RF signals to create a plurality of focused RF signals at aplurality of focal points approximately along the back surface of theSDL, the plurality of focal points having positions along the backsurface of the SDL that correspond to the plurality of incident anglesof the plurality of incident RF signals; a WAB (220) positioned adjacentto the back surface of the SDL, the WAB being in signal communicationwith the back surface of the SDL, the WAB being operable to receive theplurality of focused RF signals; a SAM (222) in signal communicationwith the WAB, the SAM being operable to electronically steer a beam(114) of a radiation pattern produced by the SAA, the SAM being operableto switch between the plurality of focused RF signals based onelectronically steering the beam; and a RAC (224) in signalcommunication with SAM, the RAC being operable to produce a received RFsignal from the plurality of focused RF signals.

Clause B, the example of clause A, wherein the SDL has a shape that isapproximately a sphere or an oblate spheroid.

Clause C, the example of clause A, wherein the SDL has a sphericityvariation that is less than approximately 0.01 wavelength of anoperating RF frequency of the SAA.

Clause D, the example of clause C, wherein the SDL has a diameter ofapproximately 152.4 mm.

Clause E, the example of clause A, wherein the SDL has a dielectricconstant approximately between 2 and 5.

Clause F, the example of clause E, wherein the SDL has a gradient ofdecreasing refractive index radially out from a center of the SDL.

Clause G, the example of clause F, wherein the SDL is a Luneburg lens.

Clause H, the example of clause B, wherein the SDL consists of amaterial selected from the group consisting of a thermoset plastic, apolycarbonate, a cross-linked polystyrene copolymer, and PTFE.

Clause I, the example of clause B, wherein the WAB (220) includes aconcave inner surface (238) positioned adjacent to the back surface(228) of the SDL (218) and a CAA (304) along the concave inner surface(238), wherein the CAA (304) is in signal communication with the backsurface (228) of the SDL (218) and wherein the CAA (304) includes aplurality of aperture elements (306(1), 306(2), 306(3), 306(4), 306(5),306(6), and 306(7)).

Clause J, the example of clause I, wherein the WAB (220) includes aplurality of waveguides (312) in signal communication with the CAA(304), wherein each waveguide (314(1)-314(7)) of the plurality ofwaveguides (312) includes a waveguide aperture in signal communicationwith the CAA (304), and wherein each waveguide aperture of eachwaveguide (314(1)-314(7)) of the plurality of waveguides (312)corresponds to an aperture element (306(1)-306(7)) of the plurality ofaperture elements of the CAA (304).

Clause K, the example of clause J, wherein each aperture element of theCAA is an elliptical aperture and wherein each waveguide aperture of theeach waveguide of the plurality of waveguides is a correspondinglyelliptical aperture.

Clause L, the example of clause K, wherein the each elliptical apertureelement of the CAA is a circular aperture and wherein each ellipticalaperture of the each waveguide of the plurality of waveguides is acorrespondingly circular aperture.

Clause M, the example of clause L, wherein the plurality of waveguides(312) includes a sub-plurality of waveguides and wherein each waveguideof the sub-plurality of waveguides includes a waveguide length (900), awaveguide directional transition (904), and a waveguide transition (906)from the circular aperture to a rectangular waveguide.

Clause N, the example of clause M, wherein the WAB is constructed ofmetal or metalized plastics.

Clause O, the example of clause M, wherein the SDL has a center (604),wherein each waveguide (314(1)-314(7)) of the plurality of waveguides(312) also includes a waveguide TO port (316(1)-316(7)), wherein eachwaveguide aperture is aligned with the center of the SDL, wherein eachwaveguide TO port is aligned the other waveguide TO ports, and whereineach waveguide TO port is in signal communication with the SAM.

Clause P, the example of clause O, wherein each waveguide is asolid-state waveguide.

Clause Q, the example of clause P, wherein each waveguide aperture is apatch antenna.

Clause R, the example of clause O, wherein the SAM includes a pluralityof selectively activated switches (1000(1), 1000(2), 1000(3), and1000(N)), wherein each selectively activated switch (1000(1), 1000(2),1000(3), and 1000(N)) of the plurality of selectively activated switches(1000(1), 1000(2), 1000(3), and 1000(N)) is in signal communication witha corresponding waveguide (314(1), 314(2), 314(3), 314(4), 314(5),314(6), and 314(7)) from the plurality of waveguides (312) of the WAB(220) and the RAC (224), and wherein each selectively activated switch(1000(1), 1000(2), 1000(3), and 1000(N)) is configured to conduct orblock a waveguide 314(1), 314(2), 314(3), 314(4), 314(5), 314(6), and314(7)) output signal from the corresponding waveguide IO port (316(1),316(2), 316(3), 316(4), 316(5), 316(6), and 316(7)) to the RAC (224).

Clause S, the example of clause R, wherein the each selectivelyactivated switch includes a switching device selected from the groupconsisting of a PIN diode, latching ferrite switch, LCV, coaxialwaveguide switch, and an RF isolator.

Clause T, the example of clause S, further including a stepper motor(1200) operatively coupled with the WAB (220) and configured toselectively rotate the WAB and SDL based on a control signal from acontroller (202).

Clause U, the example of clause T, wherein the RAC is a radial combinerin signal communication with each waveguide output port and wherein theRAC is configured to produce the received RF signal with either LHCP orRHCP.

Clause V, the example of clause A, wherein the SAA is a reciprocaldevice, wherein the SDL produces a transmitted RF signal from a receivedinput RF signal at the RAC, wherein the transmitted RF signal has atransmitted beam of the radiation pattern, and wherein the SAM isconfigured to electronically steer the transmitted beam.

Clause W, the example of clause A, further including a radome (800)disposed adjacent to the front surface (226) of the SDL (218).

Clause X, a user terminal (100) comprising: a SAA (118) for receiving aplurality of incident RF signals (230) at a plurality of incident angles(232), the SAA (118) including an approximately SDL (218) having a frontsurface (226) and a back surface (228), wherein the SDL (218) isconfigured to receive and focus the plurality of incident RF signals(230) to create a plurality of focused RF signals at a plurality offocal points approximately along the back surface (228) of the SDL (218)and wherein the plurality of focal points have positions along the backsurface (228) of the SDL (218) that correspond to the plurality ofincident angles (232) of the plurality of incident RF signals (230), aWAB (220) positioned adjacent to the back surface (228) of the SDL(218), wherein the WAB (220) is in signal communication with the backsurface (228) of the SDL (218) and wherein the WAB (220) is configuredto receive the plurality of focused RF signals, a SAM (222) in signalcommunication with the WAB (220), wherein the SAM (222) is configured toelectronically steer a (114) beam of a radiation pattern produced by theSAA (118), wherein the SAM (222) is also configured to switch betweenthe plurality of focused RF signals based on electronically steering thebeam (114), and a RAC (224) in signal communication with the SAM (222),wherein the RAC (224) is configured to produce a received RF signal fromthe plurality of focused RF signals; an RF modem (200) in signalcommunication with the SAA (118), wherein the RF modem (200) isconfigured to receive the RF signal and demodulate the received RFsignal to produce a received base-band signal (248); and a controller(202) in signal communication with the SAA (118) and the RF modem (200),wherein the controller (202) is configured to control the RF modem (200)and the SAM (222) to electronically steer the beam (114).

Clause Y, a method for receiving a plurality of incident RF signals(230) at a plurality of incident angles with a SAA (118), the methodcomprising: receiving (1302) the plurality of incident RF signals (230)at a front surface (226) of an approximately SDL (218); focusing (1304)the received plurality of incident RF signals (230) to create aplurality of focused RF signals at a plurality of focal pointsapproximately along a back surface (228) of the SDL (218), wherein theplurality of focal points have positions along the back surface (228) ofthe SDL (218) that correspond to the plurality of incident angles (232)of the plurality of incident RF signals (230); receiving (1306) theplurality of focused RF signals at a WAB (220) positioned adjacent tothe back surface (228) of the SDL (218); switching (1308) between theplurality of focused RF signals based on electronically steering a beam(114) of a radiation pattern produced by the SAA (118); and combining(1310) the switched plurality of focused RF signals to produce areceived RF signal with a RAC (224).

Clause Z, the example of clause Y, wherein switching includes conductingor blocking a plurality of output signals, from a correspondingplurality of waveguide output ports, from the WAB to the RAC.

Clause AA, the example of clause Z, further including rotating the WABand SDL with a stepper motor based on a control signal from acontroller.

It will be understood that various aspects or details of the inventionmay be changed without departing from the scope of the invention. It isnot exhaustive and does not limit the claimed inventions to the preciseform disclosed. Furthermore, the foregoing description is for thepurpose of illustration only, and not for the purpose of limitation.Modifications and variations are possible in light of the abovedescription or may be acquired from practicing the invention. The claimsand their equivalents define the scope of the invention.

The flowchart and block diagrams in the different depicted example ofimplementations illustrate the architecture, functionality, andoperation of some possible implementations of apparatuses and methods inan illustrative example. In this regard, each block in the flowchart orblock diagrams may represent a module, a segment, a function, a portionof an operation or step, some combination thereof.

In some alternative implementations of an illustrative example, thefunction or functions noted in the blocks may occur out of the ordernoted in the figures. For example, in some cases, two blocks shown insuccession may be executed substantially concurrently, or the blocks maysometimes be performed in the reverse order, depending upon thefunctionality involved. Also, other blocks may be added in addition tothe illustrated blocks in a flowchart or block diagram.

The description of the different illustrative examples has beenpresented for purposes of illustration and description, and is notintended to be exhaustive or limited to the examples in the formdisclosed. Many modifications and variations will be apparent to thoseof ordinary skill in the art. Further, different illustrative examplesmay provide different features as compared to other desirable examples.The example, or examples, selected are chosen and described in order tobest explain the principles of the examples, the practical application,and to enable others of ordinary skill in the art to understand thedisclosure for various examples with various modifications as are suitedto the particular use contemplated.

1. A steerable antenna assembly “SAA” for receiving a plurality ofincident radio frequency “RF” signals at a plurality of incident angles,the SAA comprising: an approximately spherical dielectric lens “SDL”having a front surface and a back surface, the SDL being operable toreceive and focus the plurality of incident RF signals to create aplurality of focused RF signals at a plurality of focal pointsapproximately along the back surface of the SDL, the plurality of focalpoints having positions along the back surface of the SDL thatcorrespond to the plurality of incident angles of the plurality ofincident RF signals; a waveguide aperture block “WAB” positionedadjacent to the back surface of the SDL, the WAB being in signalcommunication with the back surface of the SDL, the WAB being operableto receive the plurality of focused RF signals; a switch aperture matrix“SAM” in signal communication with the WAB, the SAM being operable toelectronically steer a beam of a radiation pattern produced by the SAA,the SAM being operable to switch between the plurality of focused RFsignals based on electronically steering the beam; and a radial aperturecombiner “RAC” in signal communication with SAM, the RAC being operableto produce a received RF signal from the plurality of focused RFsignals.
 2. The SAA of claim 1, wherein the SDL has at least one of: ashape that is approximately a sphere or an oblate spheroid; a sphericityvariation that is less than approximately 0.01 wavelength of anoperating RF frequency of the SAA; a diameter of approximately 152.4 mm;a dielectric constant approximately between 2 and 5; and a gradient ofdecreasing refractive index radially out from a center of the SDL. 3.The SAA of claim 2, wherein the SDL consists of a material selected fromthe group consisting of a thermoset plastic, a polycarbonate, across-linked polystyrene copolymer, and Polytetrafluoroethylene “PTFE”.4. The SAA of claim 2, wherein the SDL is a Luneburg lens.
 5. The SAA ofclaim 1, wherein the WAB includes a concave inner surface positionedadjacent to the back surface of the SDL and a conformal aperture arrayantenna “CAA” along the concave inner surface, wherein the CAA is insignal communication with the back surface of the SDL and wherein theCAA includes a plurality of aperture elements.
 6. The SAA of claim 5,wherein the WAB includes a plurality of waveguides in signalcommunication with the CAA, wherein each waveguide of the plurality ofwaveguides includes a waveguide aperture in signal communication withthe CAA, and wherein each waveguide aperture of each waveguide of theplurality of waveguides corresponds to an aperture element of theplurality of aperture elements of the CAA.
 7. The SAA of claim 6,wherein each aperture element of the CAA is an elliptical aperture andwherein each waveguide aperture of the each waveguide of the pluralityof waveguides is a correspondingly elliptical aperture.
 8. The SAA ofclaim 7, wherein the each elliptical aperture element of the CAA is acircular aperture and wherein each elliptical aperture of the eachwaveguide of the plurality of waveguides is a correspondingly circularaperture.
 9. The SAA of claim 8, wherein the plurality of waveguidesincludes a sub-plurality of waveguides and wherein each waveguide of thesub-plurality of waveguides includes a waveguide length, a waveguidedirectional transition, and a waveguide transition from the circularaperture to a rectangular waveguide.
 10. The SAA of claim 9, wherein theSDL has a center, wherein each waveguide of the plurality of waveguidesalso includes a waveguide input-output “IO” port, wherein each waveguideaperture is aligned with the center of the SDL, wherein each waveguideIO port is aligned the other waveguide IO ports, and wherein eachwaveguide IO port is in signal communication with the SAM.
 11. The SAAof claim 10, wherein each waveguide is a solid-state waveguide.
 12. TheSAA of claim 10, wherein the SAM includes a plurality of selectivelyactivated switches, wherein each selectively activated switch of theplurality of selectively activated switches is in signal communicationwith a corresponding waveguide from the plurality of waveguides, andwherein each selectively activated switch is configured to conduct, orblock, a waveguide and output signal from the corresponding waveguide IOport to the RAC.
 13. The SAA of claim 12, wherein the each selectivelyactivated switch includes a switching device selected from the groupconsisting of a PIN diode, latching ferrite switch, liquid crystal valve“LCV”, coaxial waveguide switch, and an RF isolator.
 14. The SAA ofclaim 13, further including a stepper motor operatively coupled with theWAB and configured to selectively rotate the WAB and SDL based on acontrol signal from a controller.
 15. The SAA of claim 14, wherein theRAC is a radial combiner in signal communication with each waveguideoutput port and wherein the RAC is configured to produce the received RFsignal with either left-hand circular polarization “LHCP” or right-handcircular polarization “RHCP”.
 16. The SAA of claim 1, wherein the SAA isa reciprocal device, wherein the SDL produces a transmitted RF signalfrom a received input RF signal at the RAC, wherein the transmitted RFsignal has a transmitted beam of the radiation pattern, and wherein theSAM is configured to electronically steer the transmitted beam.
 17. TheSAA of claim 1, further including a radome disposed adjacent to thefront surface of the SDL.
 18. (canceled)
 19. A method for receiving aplurality of incident radio frequency “RF” signals at a plurality ofincident angles with a steerable antenna assembly “SAA” the methodcomprising: receiving the plurality of incident RF signals at a frontsurface of an approximately spherical dielectric lens “SDL”; focusingthe received plurality of incident RF signals to create a plurality offocused RF signals at a plurality of focal points approximately along aback surface of the SDL, wherein the plurality of focal points havepositions along the back surface of the SDL that correspond to theplurality of incident angles of the plurality of incident RF signals;receiving the plurality of focused RF signals at a waveguide apertureblock “WAB” positioned adjacent to the back surface of the SDL;switching between the plurality of focused RF signals based onelectronically steering a beam of a radiation pattern produced by theSAA; and combining the switched plurality of focused RF signals toproduce a received RF signal with a radial aperture combiner “RAC”. 20.The method of claim 19, wherein switching includes conducting orblocking a plurality of output signals, from a corresponding pluralityof waveguide output ports, from the WAB to the RAC.